Bottom Line:
The two surgical procedures induced similar and durable changes on the gut microbiome that were not dependent on body mass index and resulted in altered levels of fecal and circulating metabolites compared with obese controls.By colonizing germ-free mice with stools from the patients, we demonstrated that the surgically altered microbiota promoted reduced fat deposition in recipient mice.These mice also had a lower respiratory quotient, indicating decreased utilization of carbohydrates as fuel.

Affiliation: The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, SE-413 45 Gothenburg, Sweden.

Mentions:
We observed significant differences in microbiota composition for RYGB versus OBS samples, but not for VBG versus OBS or RYGB versus VBG (Figure 1; Table S3). The abundance of species belonging to 29 microbial genera differed significantly between RYGB and OBS samples (Figure 1A; Table S3); in particular, the levels of several species in the Gammaproteobacteria class were higher while the levels of three species in the Firmicutes phylum (Clostridium difficile, Clostridium hiranonis, and Gemella sanguinis) were lower in RYGB versus OBS samples (Table S3). At the genus level, several facultative anaerobes in the Proteobacteria (e.g., Escherichia, Klebsiella, and Pseudomonas) were present at increased relative abundance in RYGB (Table S3). We observed a different relative abundance for several species when comparing VBG with OBS samples, and RYGB with VBG samples, although the differences were not significant after correction for multiple testing (Table S3). E. coli tended to increase, while Eubacterium rectale and Roseburia intestinalis tended to decrease in VBG compared to OBS (Table S3). Klebsiella species tended to increase, while Bifidobacterium species tended to decrease in RYGB in comparison to VBG (Table S3).

Mentions:
We observed significant differences in microbiota composition for RYGB versus OBS samples, but not for VBG versus OBS or RYGB versus VBG (Figure 1; Table S3). The abundance of species belonging to 29 microbial genera differed significantly between RYGB and OBS samples (Figure 1A; Table S3); in particular, the levels of several species in the Gammaproteobacteria class were higher while the levels of three species in the Firmicutes phylum (Clostridium difficile, Clostridium hiranonis, and Gemella sanguinis) were lower in RYGB versus OBS samples (Table S3). At the genus level, several facultative anaerobes in the Proteobacteria (e.g., Escherichia, Klebsiella, and Pseudomonas) were present at increased relative abundance in RYGB (Table S3). We observed a different relative abundance for several species when comparing VBG with OBS samples, and RYGB with VBG samples, although the differences were not significant after correction for multiple testing (Table S3). E. coli tended to increase, while Eubacterium rectale and Roseburia intestinalis tended to decrease in VBG compared to OBS (Table S3). Klebsiella species tended to increase, while Bifidobacterium species tended to decrease in RYGB in comparison to VBG (Table S3).

Bottom Line:
The two surgical procedures induced similar and durable changes on the gut microbiome that were not dependent on body mass index and resulted in altered levels of fecal and circulating metabolites compared with obese controls.By colonizing germ-free mice with stools from the patients, we demonstrated that the surgically altered microbiota promoted reduced fat deposition in recipient mice.These mice also had a lower respiratory quotient, indicating decreased utilization of carbohydrates as fuel.

Affiliation:
The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research, Department of Molecular and Clinical Medicine, Institute of Medicine, University of Gothenburg, SE-413 45 Gothenburg, Sweden.